1. Field of the Invention
This invention is directed to a method for simultaneously removing, preferably in one step, multiple impurities from crude sample containing products produced by cell culture or fermentation and, in particular, the removal of contaminants such as media components, proteins, nucleic acids, lipids, and lipopolysaccharides to ultralow levels. The product may be produced by yeast, bacterial or mammalian cells with impurities reduced to ultralow level of 91% to 99.9% as compared to the purified target substance. The invention is also directed to the products that have been purified according to this method.
2. Description of the Background
Polysaccharides, proteins and nucleic acids are synthesized by various organisms such as yeast, bacteria, and mammalian cells, which can be produced by fermentation for commercial purpose in the applications of human, veterinary or diagnostic use. Industrial production of biotechnological product from these organisms is primarily done by fermentation in the applications of products for human, veterinary or diagnostic use. In addition to biosynthetic products produced during fermentation, media nutrients and components also contribute contaminants. It is generally necessary to produce extremely pure products with ultra-low levels of impurities like protein, lipid, nucleic acid and lipopolysaccharides from crude starting materials such as fermentation fluids. In addition to biosynthetic products produced during fermentation, media nutrients also contribute contaminants. Product purification typically involves multiple and complex steps to reduce impurity levels to acceptable levels. Conventional processes for removing impurities include extraction, chromatography, precipitation, ultra-filtration, and many others. Multiple and complex steps adversely affect yield, quality, stability, processing time and process operations. Further, these processes are expensive to run, require a high degree of skill to perform, and a significant amount of time to reduce impurity levels.
U.S. Pat. No. 5,747,663 relates to a process for reduction or removal of endotoxin from biotechnologically derived therapeutic compositions. The process has incorporated incubation with non-ionic detergent prior to chromatographic purification. The chromatographic medium claimed is anion exchange material. The chromatographic purification involves use of sodium chloride salt for washing.
U.S. Pat. No. 6,428,703 relates to a process for reduction or, removal of endotoxin from biological macromolecules. The process has incorporated treatment with non-ionic detergent without incubation period prior to the chromatographic purification. The chromatographic medium is anion exchange material. The other element is the anion exchanger retains the macromolecules and the purified macromolecule is eluted from the exchanger.
Conventional purification procedures are limited and do not result in products with ultra-low levels of impurities without extensive effort. Thus, there exists a need to develop a simple purification method to achieve high purity with ultralow levels of impurities of such biosynthetic products from culture supernatants, cell extracts, plant extracts or crude lysate.